1. Field of the Invention
The present invention relates to a gloss measuring device and the like, and more particularly relates to a device that measures the gloss of an image formed on a sheet which is being transported and the like.
2. Description of the Related Art
In an electrophotographic image forming device such as a facsimile, a printer or a copying machine, especially in an image forming device used in the field of product printing, the stability of an image is highly required. Since, in recent years, it has been known that the gloss of an image somewhat affects its hue, in order to enhance the stability of an image, an operation of measuring the gloss of a formed image within a device to adjust image formation conditions and fixing conditions has been just started.
For example, in patent documents 1 to 4 (Japanese Unexamined Patent Application Publications Nos. 2002-31921, 2003-186260, 2006-267165 and 2009-68891), a technology is proposed in which the gloss of the surface of a developer image fixed on a recording medium after fixing is measured and image formation conditions and fixing conditions are controlled according to the results of the measurements.
For example, as specified in “JIS Z 8741,” the gloss of a toner image is determined by measuring the amount of light that is specularly reflected and received among light applied to the toner image. Hence, when the gloss of a toner image on an unstable sheet that is being transported is measured, since the distance from a measurement portion to the sheet and the inclination of the sheet are changed, it is difficult to obtain a high measurement accuracy.